Diaphragm for sound-boxes



provide a dia UMTED sTAfrEsrAr-ENT OFFICE.

JAMES H. ELLIS; 0F MILWAUKEE, WISCONSIN, ASSIGNOB 0F ONE-EIGHTH T0 EMIL H. STEIGER LND ONE-EIGHTH T0 EDWARD L. BEAM, BOTH OF OS'HKOSH, WISCONSIN.

emmen Fon soUND-noxns.

Specilcation of Letters Patent.

Patented Sept. 23, 1919.

Application led llarch 26, 1915, Serial Io. 17,10. Renewed Api-ll 23, 1917. Serial No. 104,049.

To all whom it may concer-m.

'Be ity known that I, .Lunas H.V ELLIS, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and Stute of Tis-cousin, have invented new and useful Improvements in Diaphragms for Sound-Boxes, of which the following is adescription, reference bein had to the accompanying drawings, whic are a part of this specification.

This invention has for its object to vide in the sound boxes of sound recor ing or reproducing instruments, a diaphragm which will have its stylus connection so arranged that in the operation of the instrument the diaphragm is ibent or warped in' stead of being convexed first on one side and then on the other. Diaphragm connections haveheretofore been so arranged as to give the center of the diaphragm a maximum movement along the axis of the sound box, but the present invention contenu lates a construction whereby a com aratively slight movement of the center o the diaphragm is produced with a greater' movement on either side thereof, the center constituting in e'ect a fulcrurn about which the parts having the maximum movenient bend in opposite directions to roduee a wave-like formation. This is e ected by the use of an angular anchor post with its link connection with the stylus lev`er offset with relation to the Stem or shank portion thereof which connects with the diaphragm so that the line of direction of force applied to the diaphragm anchor post is approximately parallel with and slightlg;r distant from the stem portion of the anchor post. Thus the line of direction of the force does not ini clude the point of connection of the connecting post with the diaphragm and. tendsto exert a lateral stress upon the connecting post as if to push or pull said connecting post over against the diaphragm, but the connection of the post with the diaphragm not permitting this, the diaphra becomes warpedor :bent in opposite either side of the connecting post somewhat in the same manner as the stretched string of a musical instrument vihrates in reverse curves on either sideof its normal position of rest.

The invention also has for its object to ihragm of sheet ivoryY as hein a most suita le material to be influenced irections on by or to produce sound wave vibrations, a further object fbeing to provide a diaphragm with notched edges to assist in maintaining its spaced relation to the walls ofthe sound Vbox while clamping it in place, such notches serving to permit the flexible gaskets to be pressed into them to constitute spacing lugs or ads for -this purpose.

ith the a'bovc and other objects in view the invention consists in the sound producmg or recording device as herein claimed and all equivalents. Referring to the accompanying drawin 1n which like characters of reference in 1- cate the same parts in the dill'erent views:

Figure 1 is a. lan view of a device constructed in accor ance with this invention;

F1 2 is a sectional view thereof applied to a und box; l A

Fig.j3 is a detail view thereof showing the anchor post;`

rFlg. 4 is a similar view of a. modified form ofithe invention as adapted for-disk record 'hul re into the notches or recesses in the edge of t ne diaphragm andserve thereby to pievent displacement of the diaphragmV which nn 'ht permit its edge to comc m contact wit the wall of the sound box, for it is well known such contact results in a very disa meuble sound being produced by the diap ragm.

.An angular anchor post is secured to the diaphragm, preferably to one side ofthe center of the diaphragm, with its eye for the connecting link o the stylus lever in the axis of the sound box or the line through the center of the diaphragm and perpendicular thereto. This anchor post may be, and preferably does consist of a strip 14 of the material of which the diaphragmls made cut to a tapering formand inserted through a, slot in the d1aphragm of proper dimen- .sions to make a snug lit therewith, the

. at the other side ofthe diaphragm the strip 14 has one 'or more indentations 16 f ormed therein andthe cement .is filled therein and along the 'meeting edg between the strip 14 and the diaphragm form a, lillet therefor, and all serving to rigidi secure the strip 14 to the diaphragm. lthough the strip 14: is oomparativel" broad and dat it is for convenience referre to as the shank or stem portion of the anchor post of which it forms a part and near its outer edge 1t has an arm 17 ofsimilar material mounted in it in the same mannerrthat it is mounted in the diaphra m, and said 'arm lies in aplane ex pcndicu ar to the diaphragm and inclu ing the axis thereof. The strip or plate 14 forniing the stem of the anchor post is positioned a short distance to one side of the center of the diaphragm and the arm 17 is provided with an opening in the axis of the diahragm or the axis of the sound box which is considered to be the line through the center of the diaphragm and perpendicular therewith, Through this hole is, connected a connecting link 18 of the usual stylus lever 19.

In operation the movements of the stylus lever incident to the irregularities in Vthe path of travel of the stylus carried thereby are transmitted to 'the diaphragm, but instead of the connection between the stylus lever and the diaphragm bein direct it is made through the angular anc or post, and the connection with such anchor post being out of alinement with the stem portion thereof the tendency is to bend the anchor osi, over against the diaphragm and as this is resisted by the firm connection between the anchor post. and the diaphragm a distortion of tho diaphragm is produced to give it a warped or wave-like shape with the portion on one side of the anchor post couvexcd in one direc-tion and the portion on the other side convexed in the opposite direction. A reversal in the direction of the force applied to the diaphragm through the operation of the stylus lever will of course reversc the direction of the bending of the dia plwagin so that the iliaphra m vibraties with a Wave mol-ion with one si c above the normal position and the othcf-side below the normal position in one instant and these posi tions rcsersed immediately following. This diaphragm construction produces sounds free from mechanical blast and reiiiailrahly true in quality tolhe original tones, even with the extremely high and extreme] low notes. While the anchor post may c centrally asienta positioned on the diaphragm, it is preferred to position it to one side of theI center, asf

shown, with the stylus connection in the line of the axis of the diaphragm as it is found that the results are somewhat better in this location of the parts.

., The principles of this invention are ap f this construction the same movements of tht diaphragm are produced with the same boneficiul results and advantages.

'While the diaphra m and the anchor post may be of other suitable materials it 'is found that ivory is superior for the purpose.

The anchor 'post is itself flexible, though rigidly .connected with the flexible diaphragm, and the manner in which it is connected assures a sutliciency of responsive movement of the diaphragm to give volume as well as quality and accuracy in the reproduced sound.

The angular sha e of the anchor post is 1 not alone responsib e for the warping client of the diaphragm, for this eiert would bo lost with an angular anchorpost if the line of direction of the force applied thereto should be such as to intercept the point of connection of the anchor ost with the diaphragm. The warping e ects might also he produced by an anchor 0st whichJ though not angular, is in an ob ique position with respect to 4the diaphragm, as. shown in Fig. 6, or has the line of force oblique with rcspcct thereto, as shown in Fig. 7, so that in either case such line of force does not pass through the dia connectiin Between t ic anchor post and the dinphra m. I

What claim as new and desire to secure by Letters Patent is:

1. The' combination of a diaphragm, a

thin sheet of flexible material, a stylus ophragm at the point. of

erated member, and anl anchor post connectl,

ed with the stylus operated member and secured to and solely supported by the thin sheet of flexible material at one side of the line of movement of the connection between the stylus operated member and the anchor ost. i p 2. The combination of a dia hragm disk of thin flexible z'naterial2 a sty us operated means having a direction of movement approximately in the axisof the disk, and an anchor post secured to and solely supported by the disk at a distance from the center of the disk and having connection with the said means in the line of the axis of the having a laterally .projecting arml reaching to the axis of the dlsk, and'astylus operated means connected with said 'arm at a point laterally extending arm reaching to the axis of the disk, and #stylus operated means connected with the arm at a point near the axis of the disk.

` 6. The combination of a diaphragm disk of thin flexible material having a slot therethrough, a tapering strip of flexible material fitting in the slot and secured to the disk, a tapering arm fitting in an opening of said strip and projecting laterally therefrom, and a stylus operated means connected with the arm at a distance from the strip.

In testimon whereof I aliix my signature 30 in presence o a witness.

JAMES H. ELLIS. Witness:

KATHERINE Hour. 

